Talk about LCD TV in terms of knowledge

* 1 resolution for LCD televisions, the resolution is one of the important parameters. Traditional CRT TV resolutions supported more flexible, and the pixel pitch of the LCD TV has been fixed, supported display modes, unlike CRT TV so much. The best resolution of LCD TVs, also called maximum resolution, in this resolution, the LCD TV to show the best image.
    When the LCD TV exhibits a lower resolution display mode, there are two ways to display. The first one is centered: for example, SVGA 800 × 600 screen display on the XGA 1024 × 768 screen, only the center of the screen 800 × 600 pixels is presented, the other has not been rendered pixels will remain dark. At present, the method is less used. Another called extended display: in the display below the optimal resolution of the screen, each pixel through a differential algorithm to expand into adjacent pixel display, so that the entire screen is filled. This also makes the picture lost its original clarity and true color.
Currently there are LCD TV resolution 1280 × 768 and 1280 × 1024 several, along with new products continue to emerge, the resolution also is improving.
2 * HDMI digital high-definition
That is the future of high-definition television standard HDMI digital interface, just one HDMI cable to transmit high-definition digital video and audio signals, effectively solve the messy wires behind home entertainment system and tangled problem.
3 * input terminal
  LCD TV input terminal is the interface between the received signal, the receiving terminal allows full LCD TV and other devices to connect easily.
    Standard video input (RCA): also known as AV interface, usually in pairs of white and yellow audio interface video interface, it is usually RCA (commonly known as RCA) connection, simply with the use of standard RCA AV cable to connect to the corresponding interfaces. AV interface separation of audio and video transmission, which avoided because the audio / video mixing interference caused decline in image quality, but because of AV transmission interfaces is still a luminance / chrominance (Y / C) video mix signal, still need to display its bright / color separation and chroma decoding can imaging, this first hybrid separation process will inevitably result in further loss of color signal, the color signal and luminance signal will be a great opportunity for mutual interference thus affecting the quality of the final output image. AV also has a certain vitality, but because of its own Y / C mix this insurmountable disadvantage can not be used in the pursuit of visual limit occasions.
    S-Video Input: S-Video specific English name called Separate Video. In order to achieve better video effect, people began to search for a more efficient and excellent higher definition video transmission, which is currently flourishing S-Video (also known as two component video interface). Separate Video Video significance is to separate the transmitted signal, that is, will be the basis chrominance signal C and the luminance signal Y AV interface separation, and then were different channels, while it appeared and developed in the last century, 90 years late usually uses the standard 4-cell (without sound) or extended 7-core (including audio). Graphics and video devices with S-Video interface (such as analog video capture / editing card TV and quasi-professional Monitors TV card / TV boxes and video projection equipment, etc.) currently has more common, compared with the AV interface because it does not then Y / C hybrid transmission therefore no longer be bright separation and decoding, and use separate transmission channels largely avoided in the video device signal crosstalk and image distortion, greatly improved the image clarity. However, S-Video still be two color difference signals (Cr Cb) produced by mixing all the way chrominance signal C, for transmission and then decoded in the display device for the Cb and Cr are processed, and how many will still bring some signal loss distortion (when this distortion is small but under strict broadcast video equipment for testing are still being found), and because of mixed Cr Cb chroma signal bandwidth is result there are certain limitations, so S -Video Although relatively good but still far from perfect. S-Video, while not the best, but considering the other factors of the current market conditions and overall costs, it is the most common video interface.
    Video Component Input: There can be seen in some professional video workstation / editing card or high-end professional video equipment DVD players and other appliances have YUV YCbCr Y / BY / BY interfaces such as identification tags, although the labeling method and joint shape each different but they are referring to the same color port interfaces (also called component video interface). It is commonly used both YPbPr and YCbCr logo, the former said progressive scan component output, which represents the interlaced component output. Seen from the above relations, we only need to know the value of Y Cr Cb will be able to get the value of G (ie, the fourth equation is not necessary), so the video output and color processing on harmonization ignored poor Cg and keep only green Y Cr Cb, and this is the basic definition component output. As S-Video advanced product color output S-Video transmission color chroma signal C is decomposed into Cr and Cb, thus avoiding the two color mixed and separated again decoding process, but also to maintain the maximum chrominance channels Bandwidth, only after anti-matrix decoding circuit can be reduced to RGB RGB signal imaging, which minimizes the video source to the video signal path between the display image, avoiding the cumbersome transfer process brought about image distortion, so the interface mode color output of a variety of video output interface is the best kind.
Since the liquid crystal TV can be connected to the computer, it is also still possible with the same port connected to the computer, including the audio signal input terminal and connected to the computer:
    VGA Input: VGA 15pin connection interface using the asymmetric distribution of their works: within the memory is stored in a digital format image (frame) signal in RAMDAC after the analog modulation into an analog high-frequency signal, and then output to the projector imaging, this VGA signal at the input terminal (inside the projector), they do not like the other video signals that go through the conversion matrix decoding circuit. From the front VGA video imaging principle known video transmission is the shortest, so the VGA interface has many advantages, such as no crosstalk loss and so no separate circuit synthesis.
    DVI input: DVI interface is mainly used with a digital display computer graphics output is connected to display RGB signal from the computer. DVI (Digital Visual Interface) digital display interface, by September 1998, at the Intel Developer Forum established Digital Display Working Group (Digital Display Working Group, referred DDWG), developed by digital display interface standard. DVI digital terminal is better than the standard VGA terminal signals, digital interface ensures all content digital format for transmission to ensure the integrity of the host to monitor the transmission of data (no interference signal into), you can get a sharper image.
4 * Aspect Ratio
  We generally screen width and height ratio is called the aspect ratio (Aspect Ratio, also known as the aspect ratio, or the ratio of the screen is called). Currently Aspect Ratio LCD TVs are generally 4: 3 and 16: 9.
From the late 19th century until the 1950s, almost all of the film's aspect ratio is standard 1.33: 1 (precisely, 1.37: 1, but is referred to as the standard 1.33: 1). That is, the width of the movie screen is 1.33 times the height. This is sometimes expressed as the ratio of 4: 3, that is a width of 4 units and a height of 3 units. 1950s, the nascent television industry is facing what the TV screen ratio adopted as standard issue. In order to facilitate the movies onto the TV screen, National Television Standards Committee (NTSC) standard Institute finally decided to adopt as the standard TV ratio, which is the 4: 3 aspect ratio television origin. This ratio until today is still the dominant standard TV.
    Because of this tradition, we now received TV is such a ratio, the ratio of screen LCD TV is also still in 4: 3 based. But the real widescreen movie generally, will be converted to wide screen movie 4: 3 will always cause loss of picture quality, shape or content, in order better to watch on the TV movie program, 16: 9 screen TV proportion appeared, and because the future of high-definition television will primarily use the 16: 9 aspect ratio, so far there are some LCD TVs use such a screen ratio.
5 * Contrast
  The contrast on the screen is the same point, the brightest (white) ratio darkest (black) brightness, high contrast ratio means that a relatively high luminance and color rendering bright degree.
Excellent quality and excellent LCD TV panel backlight brightness, both of which can be obtained with reasonable full color bright and clear picture. Currently most of the desktop brightness of LCD TVs ranging from 150 to 300cd / between m2, no matter how high up to 350cd / m2 or 500cd / m2; and more contrast is 200: 1 to 500: 1.
* Screen size 6
  It refers to the length of the LCD screen diagonal in inches. And the TV, large LCD TV viewing experience better, more conducive to viewing distance farther, or watch in the spacious environment. But the influence of the liquid crystal panel manufacturing process, oversized LCD screen costs will soar, and now the mainstream product master screen size of 20 inches.
The reaction time is 7 *
  The so-called reaction time of each pixel of the liquid crystal television of the input signal reaction speed, that is, pixel from dark to light or from light turned dark time required (the principle is the voltage applied to liquid crystal molecules, the liquid crystal molecules are twisted and replies). Often say 25ms, 16ms means of the reaction time, the shorter the time the user will not see the more dynamic picture tailed Movies dragging feeling. The reaction time is generally divided into two parts: the rise time (Rise time) and fall time (Fall time), and is represented in the sum of them prevail.
   CRT television, as long as the electron beam hitting the phosphor emitting instantly, and the residual glow time is extremely short, and therefore the reaction time is only the conventional CRT TV 1 ~ 3ms. Therefore, the reaction time in the CRT television is generally not been mentioned. And because the LCD TV is the use of the liquid crystal molecules are twisted to control light off, and the liquid crystal molecules to reverse a process, so the response time of LCD TV to be significantly longer than CRT.
From 25ms to 12ms earlier well-known 16ms then recently appeared, the reaction time is shortening, stereotypes LCD TV is not suitable for entertainment are suffering huge challenge. You can do a simple conversion: 30 ms = 1 / 0.030 = per second display screen 33; 25 ms = 1 / 0.025 = per second display screen 40; 16 ms = 1 / 0.016 = per second display 63 frame picture; 12 ms = 1 / 0.012 = 83 images displayed per second. As can be seen the birth of a great progress means 12ms LCD manufacture.
    In fact, we said above 12ms response time is the time for switching between black and white screen desired, this all-white drive voltage required for switching a black screen is relatively high, so the switching speed comparison fast, can reach 12ms; and the practical application of mostly gray-scale screen to switch (and its essence is not completely reversed LCD, not entirely translucent), the required drive voltage is relatively low, so the switching speed is relatively slow. So together, in grayscale screen 75Hz refresh rate has to meet the needs of a 12ms LCD panel.
According to the data show that:
    The reaction time is 30 ms = 1 / 0.030 = 33 per second television capable of displaying the picture, which has been able to meet the needs of the DVD player;
    The reaction time is 25 ms = 1 / 0.025 = per second TV screen can display 40, a DVD player and fully meet the needs of the vast majority of movies or games.
* 8 "bass hammer" fidelity
   Labyrinth cavity has a longer channel bass, bass by multiple reflections within the cavity, multiplied strengthen, and then through the reflective walls and desktops, the weight of the air sound with greatly enhanced, bass grand, shocking.
20 years of professional audio design experience, designed to shock as the series of labyrinth design "bass hammer" sound system, groundbreaking ultra-thin LCD TV stereo bass performance is greatly enhanced.
Especially the use of "drive" king NdFeB material patent horn, driving energy is eight times that of ordinary speakers, the bass prominent exception, the use of high elastic rubber small cell foam structure, effectively reduce the noise distortion, more clear and smooth midrange.
Built-in BBE electronic adjustment system, intelligent correction and recovery phase deviation signal loss and sound system, the correct restore the original sound, the true nature to reproduce the human voice.
Built-in high efficiency digital power amplifier and sub seamless integration of digital sources, effectively reduce interference between transmitted signals. Amoi "surprise as the series of" truly digital TV HI-FI audio technology.
9 * Receiving System
  The television video signal is an analog signal, the analog video from the sync data and the video data, and is used to properly display the image receiving side. Details of the signal depends on the application's video standard or "standard" --NTSC (National Television Standards Committee, National Television Standards Committee), PAL (Phase Alternating Line, Phase Alternate Line) and SECAM (sequential color television transmission and storage system a TV system used in France, SEquential Couleur Avec Memoire). Due to the use of different formats, there are incompatibilities. Take the resolution, the some standard 625 lines per frame (50Hz), while others are only 525 lines (60 Hz) per frame, the former is PAL system, which is the standard used in North America and Japan, collectively known as NTSC .
In addition, NTSC standard also provides video sources per second to send 30 complete image (frame). If for no other treatment, flicker can be very serious. To solve this problem, and each frame is divided into two parts, each part of the 262.5 lines. All part of an odd line, the other part is all even lines. When displayed, the first scan odd lines and then the even-numbered scan lines, can effectively improve the stability of the image display to reduce flicker. The world of color television there are three main formats, namely, NTSC, PAL and SECAM formats, currently three formats can not be unified. China's use of the PAL-D system, so its use in our LCD TV at least compatible PAL-D format. LCD TVs are generally more compatible TV system, but before buying the best reconfirm.
10 * Backlight Type
  Backlight types are divided into: CCFL and LED two types
CCFL cold cathode fluorescent tubes (Cold Cathode Fluorescent Lamp)
Cold cathode lamp is a new type of lighting; Since the CCFL lamps have a small, simple structure, small tube surface temperature, high surface brightness lamp, easily processed into a variety of shapes (straight tube-shaped, L-shaped, U-type, ring, etc.); long life, good color, light uniformity, etc; it is also the current TFT-LCD (liquid crystal display) over the light source, while widely used in advertising light boxes, scanners, and other uses backlight .
CCFL cold cathode Why is this cold mean?
And "cold" and "hot", as usual electron-emitting material, namely the cathode, two kinds of cold and heat points we usually understand.
Hot cathode, current mode refers to the cathode heating at temperatures above 800C, so that electrons inside the cathode due after obtaining the kinetic energy is converted to heat energy emitted outside;
Cold cathode means without heating the cathode, but to use an electric field to control the potential changes in the interface, electrons inside the cathode potential energy is converted into kinetic energy and emitted outside.
Two kinds of cathode biggest feature is that you can use low-voltage hot cathode can generate an electron emission, and the cold cathode often need to produce a high voltage electron emission.
The relatively short life of hot cathode, cold cathode lifetime longer. Therefore, in the CCFL, often using a cold cathode.
CCFL principle should be applied when the high pressure in the tube ends, resulting in secondary electron emission after high-speed crash within a few electrons lamp electrodes to start discharge, due to the lower cathode temperature, so the name.
Secondary electron emission cathode is an important process CCFL.
Glow discharge, Townsend ionization coefficient is the third ion bombardment secondary electron emission coefficient of the cathode surface, the process is generally the cathode surface ion Auger neutralization process (Auger neutralization of an ion), also known as Hagstrum theory (see: Homer D. Hagstrum, "theory of Auger Ejection of Electrons from Metals by Ions," Phys Rev. 96, (1954) 336-365.).
When the positive ions move to the cathode surface of the cathode material free electrons in the compound, while the release of the ionization energy; in other post-cathode electron ionization can obtain this, overcome the surface potential barrier deviates outward emission cathode, which is the so-called two secondary electron emission, field emission is an indirect process. At the same time, positive ions will form a positive ion cloud near the cathode surface area, the positive ion cloud relative to the cathode as a positive electric field is applied, it is also a direct field emission. So, CCFL and can then use DC drive, AC drive can also be used.
The surface of the cold cathode discharge process is extremely complex. In this case, the landlord for the inconvenience dwell too much professional content, so I said to replies table, the only hope for non-professionals easy to understand this "cold" different "hot" only.
Cold, low-calorie low power consumption, the most important meaning.
1 . Whether it is about the cold cathode tubes cold cathode tube or a hot cathode tube, it is the principle on the terms of the fluorescent tube, the luminous and the general principles of the same fluorescent tube. It ran from the electrode to the electron impact of mercury (xenon can also be used), to stimulate the release of mercury so that ultraviolet rays, ultraviolet radiation to the fluorescent coating on the inside of the glass tube body become visible.
A big difference between the cold cathode tubes and hot cathode tube that electrode portion. Simply because of the cold cathode tube structure, so it can be very thin fluorescent tubes. Since the electron emission electrode is not hot electron emission, so called cold-cathode tube (ColdCathodeFluorescentLamp, cold cathode fluorescent lamp). On the other hand, the general fluorescent tube due to its electrodes glowing filament, causing it to heat up and hot electron emission, so called hot cathode tube (HotCathodeFluorescentLamp - HCFL).
2 . Applications of the cold cathode tubes and hot cathode tube
Hot cathode tube due to the construction of its electrodes can not be miniaturized, it is not suitable for thin fluorescent tubes. Therefore, the heat pipes are mainly used in high-power cathode fluorescent tube. General lighting with fluorescent tube almost all this. On the other hand, the cold cathode tube due to the fine pattern having the characteristics, mainly used for liquid crystal back light (backlight). Moreover, lately you can see the color of the cold cathode tubes used in automotive and other decorations, by everyone's attention. If you see through the car from the side in blue or purple decorations, it is a cold cathode tube. In addition, compared with the hot cathode tube, cold cathode tube has a long life, small size, low power features that are often used to living light, etc., the increasingly widespread use.
3. The heat of the cold cathode tube is easily misunderstood: usually think of the cold cathode tube cathode cooler, so the heat generated at the cathode may be relatively small. This is a great mistake, heat the cold cathode tube cathode occurred much more than a hot-cathode tube of the same power. Cold cathode tube and hot cathode tube internal voltage gradient as shown in Fig. Here, note that Italy cathode voltage drop and voltage drop arc column. Whether a cold cathode tube or a hot cathode tube, in fact, consumption of energy into light portions are portions of the arc column. Since the cathode voltage drop is not used for the light emitting portion, so that all energy is converted into heat are wasted. The cathode voltage drop on the small hot cathode tube, cold cathode tube and in the large. Namely: the efficiency of the cold cathode tube cathode tube heat low. Cold-cathode tube useless consumption of energy in the vicinity of the cathode, as a result, a "cold" cathode tube is hot electrode. Therefore, the cold cathode tube design of the machine, pay attention to make good heat near the cathode.
4. Electrical characteristics of the cold cathode tube
Because of the cold cathode tube cathode voltage drop is large, in order to improve efficiency, so increasing the arc column (Japanese: Sunshine column) impedance values, can make the most of the actual energy consumption in the visual light. As a result, the tube current becomes smaller, the resistance value (impedance) increases. Chart 2 backlight lamp current -? Tube impedance characteristic impedance of the cold cathode tube if you want to use a laptop computer, typically 5 0KΩ 2 00KΩ. When compared with this, a hot cathode tube used for general illumination 2 00KΩ? About 1KΩ. If the tube current increases,
It will dramatically reduce the resistance value, while a negative impedance characteristic. Cold cathode discharge tube voltage laptops with typically about 700V. Is about 70V when a hot cathode tube? About 140V. Tube voltage cold cathode tube high lamp impedance (resistance) is high, it will be strongly influenced by stray capacitance.
Impedance Generally, a cold cathode tube (impedance) (tube voltage / tube current) to tube current of 5 - / proportional to the fourth power, which is well known. In addition, the minute current field of tube voltage is known to be the starting voltage, or voltage lighting. Lighting voltage in the sense that once the cold cathode tube if not placed in such a situation is not a high-voltage discharge, but the cold cathode tube is still great doubt. This is because the cold cathode tube assembly after the backlight, this feature will be a big change.
LED light-emitting diode (Light Emitting Diode) is widely found in everyday life, such as household appliances, lights, fog lights and other car defense. The most notable feature is the LED long life, high photoelectric conversion efficiency.
    In some semiconductor materials, PN junction, the injected minority carrier and majority carrier recombination, when will the excess energy released in the form of light, which converts electrical energy directly into light. PN junction reverse voltage, minority carrier injection is difficult, it is not light. This use of injection electroluminescent diodes called the principle of making light-emitting diodes, known as LED.
LED luminous color and luminous efficiency and production of LED materials and processes related to the widely used red, green, and blue. Because LED low voltage (1.5-3V only), you can take the initiative and have a certain luminous brightness, Brightness and adjust the voltage (or current), in turn, impact resistance, anti-vibration, long life (100,000 hours), so large display device, there is no other display and LED display match.
   The red and green LED together produced as a pixel display called dual color screen or pseudo-color screen; red, green and blue LED tube put together as a pixel display called the three primary colors or full-screen color. Production of indoor LED screen pixel size is generally 2-10 mm, often used to produce several different color of the LED die into one package, outdoor LED screen pixel size, mostly 12-26 mm, each pixel is composed of several various color LED, which is common product of say pixel tube or pixel module.
LED display if you want to display an image, you need to make up each LED light emitting brightness of the pixels must be able to adjust its regulation sophistication that the gray level. The higher the gray level, the displayed image more delicate, the color is richer, the corresponding display control system is also more complex. In the current technology level, 256-level grayscale images, color transition has been very soft, Image restoration results were satisfactory.
Data show, LED light source 87% energy saving than incandescent, fluorescent energy-saving than 50%, while life expectancy of 20 to 30 times longer than incandescent, fluorescent longer than 10
Times. LED light source due to energy saving, environmental protection, long life, safe, fast response, small size, rich colors, controllability, and other unique advantages, it is considered to be electricity fall of the best ways to achieve.
11 * Personal Emergency
   DVI can transmit video signals, audio signals can not be transmitted, compared with DVI: The biggest advantage is that HDMI interface can simultaneously transmit audio and video signals and smaller.
12 * viewing angle
  Viewing angle is the angle that a user can observe all of the content on the screen clearly from different directions. By providing the light source by refraction and reflection of existing liquid crystal display output after a certain direction, beyond the scope of this watch will produce color distortion, CRT TV will not have this problem.
    Two indicators include LCD TV viewing angle horizontal viewing angle and vertical viewing angle, horizontal viewing angle in the vertical normal display (ie, the middle of the display vertical imaginary line), whichever is in perpendicular to the normal left still be able to see the normal position of the right side or at an angle on the display image, the angle range is the horizontal viewing angle liquid crystal display; if the same subject to the normal level, the vertical viewing angle is called the vertical viewing angle . Generally, the contrast viewing angle is changed to a reference standard. When the viewing angle increases, the position to see the display image contrast will be reduced, and when the angle is increased to a certain extent, decreased contrast to 10:1 when this angle is the maximum viewing angle of the liquid crystal display.
    Currently viewing angle of LCD TVs on the market are symmetrical, but not necessarily symmetrical up and down, and is often less than the vertical angle around the angle. When we say that the view angle is about 80 degrees, the normal screen showing standing starts (Monitor is the middle of the imaginary line) can still clearly see the screen image 80 degrees position. Larger perspective, the better the viewing angle, LCD monitors also more applicable. Currently on the market most of the viewing angle of 120 degrees or more products, some products reached more than 140 degrees.
13 * Voice output power
   LCD TV in order to play a sound, so are at least two with built-in speakers. Maximum power is determined by the sound of the speaker can be issued strong feeling that the voice on the speaker issued to have much power to shock.
    According to international standards, there are two power Tagging: Rated power (RMS: RMS sine wave) and the instantaneous peak power (PMPO power). The former refers to the nominal range drive 8Ω speaker provides a continuous analog signal waveform, in spaced and repeat after a certain number of speakers of any damage to the maximum electric power does not occur; the latter refers to the speaker can withstand short-term maximum power . US Federal Trade Commission regulations in 1974, the power calibration standards: two-channel speaker drives a 8Ω load, in the range of 20 ~ 20000Hz effective wattage is less than 1% of the measured harmonic distortion, namely the amplifier output power, the power that marked the rated output power. Typically businesses in order to cater to consumer psychology, marked instantaneous (peak) power, usually about 8 times the rated power.
    Since the main effect of the LCD TV is not listening to music, so the sound is not very important power, by contrast, the sound quality may be more important than others. The general LCD TV speaker power from 2 to 10W.
14 * 60 times more fresh color
   Amoi unique fresh color technology uses 10-bit processing technology to really achieve the world's highest 10.7 million color display series. Vivid color vividness of people reached in the past 60 times.
15 * Number of colors
   Total number of colors is the number of colors on the screen can display. For each pixel on the screen, the 256 colors to use 8-bit binary number, ie 8 power of 2, so we put a 256-color bitmap graphics is called 8; if the color of each pixel with a 16-bit binary number that we call it 16 bitmap that can express the power of 16 ie 65,536 colors 2; and 24-bit color map, can be expressed 16,777,216 colors. The general LCD TVs generally support 24-bit true color.